Electronic systems such as computer systems frequently include electrical components that have different power supply requirements. To meet these requirements, many computer systems include power supply systems that have distributed power architectures. With distributed power architectures, an AC to DC power supply is used to generate intermediate voltages, and additional DC to DC voltage converters are used to generate signaling voltages. The DC to DC converters typically convert a higher DC voltage level to a lower DC signaling voltage level. The input voltage for each DC to DC converter is typically supplied from the AC to DC power supply or from other DC to DC converters.
One problem that arises with distributed power architectures is that if one converter is faulty, multiple converts may shut down as a result, thereby making it difficult to determine which converter is the faulty converter. This is because each converter usually relies on one or more other converters in order to generate an output voltage. For example, power converters can have inputs which include a source voltage rail, a bias rail to power electrical circuits that are internal to the power converter, and other rails which provide enable inputs. If any of these inputs fails, the power converter will not operate and will shut down. Furthermore, other power converters that receive inputs from the faulty power converter will also shut down. As a result, with distributed power architectures, if one power converter shuts down, other power converters will shut down almost simultaneously, thereby making a diagnosis of which power converter is the faulty converter very difficult.
Several approaches have been employed to diagnose failed power converters in distributed power systems. One approach is to monitor each power converter during normal operation. When one power converter has an output voltage which goes out of regulation or fails, other power converters usually will also fail. Since every power converter is being monitored, the first power converter to fail can be determined. A disadvantage of this approach is that very precise timing resolution is employed to determine the first power converter to fail. For example, if the status of each power converter is obtained by polling the power converters at periodic intervals, if several power converters fail within a period of time which is less than the periodic interval, the power converter that failed first will not be able to be identified.
Another approach is to employ a voltage monitor that can monitor a number of power converters and provide a warning if any of the power converters goes out of regulation or fails. Voltage monitors are typically designed to support a fixed number of power converters and can identify the first converter to fail in a group of power converters. A disadvantage of employing voltage monitors is that if fewer than the fixed number of power converters is used, the relative cost per converter is increased, and if greater than the fixed number of power converters are used, it can become difficult to determine which power converter was the first to fail.